Who is this product good for? Anyone looking for an easy, reliable solution to drinking in aero. Personally, I have to have a straw up front, in one form or another. It makes it so easy to drink, and that convenience is invaluable to me. Now, with the straw requirement in place, the question becomes what kind of bottle to use. And the TorHans is an excellent choice. It has a solid, engineering-based design, keeps things minimal without sacrificing usability, and is utterly reliable.
In my mind, the big question is how this product stacks up against the Speedfil A2. Aerodynamics aside, I see the situation as follows: the Speedfil's big advantage is that it mounts in a standard bottle cage, meaning you can convert your front end setup depending on the race you're doing. If you want to ditch the A2 for a standard bottle, it's no problem. The TorHans, on the other hand, has the advantage that its straw sits vertically inside the bottle, so you'll never run into the problem of getting those last few drops out (when low, the Speedfil will be susceptible to steep gradients moving the liquid to the wrong side of the bottle). I find myself prefering the sleek look of a BTA bottle like the A2, but reliable drinking is a feature whose importance can't be overestimated, and the TorHans Aero 20 has that in spades.